This project concerns the systematic study of the relationship between differential light-scattering and red cell shape changes with the help of computer image processing in an attempt to develop a useful experimental technique for continuous monitoring of the sickling process. A laser differential light-scattering system has been constructed using a 10 mwatt He-Ne laser. The system is capable of measuring the scattered light intensity from 0 to plus or minus 177 degrees with a scanning rate from 0.01 degrees single step to 20 degrees/sec. The resolution of the differential scattering angle is approximately 0.5 degrees. Differential light-scattering patterns have been obtained for normal and sickle cells at 1% hematocrit. Experimental results indicate slight attenuation of the differential scattered light intensity at all angles as the red cells go from fully oxygenated to fully deoxygenated states. Rapid changes of the scattered light intensity at small angles are observed with pH variations from 6.6 to 8 and are attributed to small changes (2 to 4%) of red cell volume and pH according to the Donnan equilibrium effect. Significant changes in the scattered light intensity of small angles have also been observed with the occurence of sickling.